Not Applicable
Not Applicable
Not Applicable
The present invention generally relates to electrical resistance heating apparatus and, more particularly, to flexible heaters having field replaceable thermostats.
In many processing industries, it is advantageous to heat contents such as fluids located within vessels such as pipes, ducts, conduits, and the like. Often, a flexible heater such as a heating jacket, is disposed about the vessel so that, when activated, the flexible heater elevates the temperature of the vessel and thus the contents located therein. The heating jacket typically includes a flexible heating element enclosed in multiple layers of flexible high temperature cloth and insulation. The heating jacket can also include a thermostat enclosed within the layers to regulate the temperature of the heating element.
While these heating jackets perform their intended purpose, their life can be limited by the failure of the thermostat. When the thermostat fails, the heating jacket must be removed and replaced. While the heating jacket may be returned to the producer for replacement of the thermostat, time and resources must be expended to remove, repair, and replace the heating jacket. Additionally, spare heating jackets must be available for immediate use if down time of the processing equipment is to be minimized. Accordingly, there is a need in the art for an improved flexible heater wherein the thermostat is replaceable in the field.
In accordance with one aspect of the present invention a heating jacket for use on a processing vessel includes a flexible heater jacket having a plurality of layers, a flexible heating element positioned within the layers, and a thermostat positioned within the layers and electrically connected to the heating element for regulating the heating element. An access opening is formed in at least one of the layers to provide access to the thermostat positioned within the layers. An access cover is moveable to selectively cover and uncover the access opening whereby the thermostat is replaceable by uncovering the access opening.
According to another aspect of the present invention, a heating jacket includes a flexible heater jacket having a plurality of layers, a flexible heating element positioned within the layers, and a thermostat positioned within the layers and electrically connected to the heating element for regulating the heating element. An access opening is formed in at least one of the layers to provide access to the thermostat positioned within the layers. An inner cover selectively covers and uncovers the access opening and an outer cover selectively covers and uncovers the inner cover.
According to yet another aspect of the present invention, a heating jacket includes a flexible heater jacket having a plurality of layers, a flexible heating element positioned within the layers, and a thermostat positioned within the layers and electrically connected to the heating element for regulating the heating element. A pair of generally parallel strips are secured to the layers. The thermostat has a mounting bracket extending below the strips to secure the thermostat to the layers.
According to even yet another aspect of the present invention, a method of replacing a thermostat of a heating jacket for use on a processing vessel includes the step of providing a heating jacket having a flexible heater jacket with a plurality of layers, a flexible heating element positioned within the layers, a thermostat positioned within the layers and electrically connected to the heating element for regulating the heating element, and an access cover movable to selectively cover and uncover an access opening formed in at least one of the layers to provide access to the thermostat. The method also includes the steps of moving the access cover to uncover the access opening, replacing the thermostat while the access opening is uncovered, and moving the access cover to cover the access opening after the thermostat is replaced.
From the foregoing disclosure and the following more detailed description of various preferred embodiments it will be apparent to those skilled in the art that the present invention provides a significant advance in the technology and art of flexible heaters. Particularly significant in this regard is the potential the invention affords for providing a high quality, reliable, low cost, field repairable assembly. Additional features and advantages of various preferred embodiments will be better understood in view of the detailed description provided below.